The objectives of the research are to obtain a better understanding of the specific viral etiology of viral respiratory diseases and their biologic expression of infection, epidemiology, and methods of prevention or cure. The antigenic properties of rhinoviruses will be compared with the prototype strains; influenza viruses and the changing antigenic composition characterized. The research is also concerned with definition of immunologic host responses to viral respiratory infection. Antibody, interferon, delayed hypersensitivity, and primary cellular resistance are mechanisms being studied. Where appropriate, new vaccines and antiviral drugs are investigated.